1. Technical Field
The present invention generally relates to information services and in particular to techniques for implementing information services with tenant specific service level agreements.
2. Description of the Related Art
In general, cloud computing refers to Internet-based computing where shared resources, software, and information are provided to users of computer systems and other electronic devices (e.g., mobile phones) on demand, similar to the electricity grid. Adoption of cloud computing has been aided by the widespread adoption of virtualization, which is the creation of a virtual (rather than actual) version of something, e.g., an operating system, a server, a storage device, network resources, etc. A virtual machine (VM) is a software implementation of a physical machine (e.g., a computer system) that executes instructions like the physical machine. VMs are usually categorized as system VMs or process VMs. A system VM provides a complete system platform that supports the execution of a complete operating system (OS). In contrast, a process VM is usually designed to run a single program and support a single process. A characteristic of a VM is that application software running on the VM is limited to the resources and abstractions provided by the VM. System VMs (also referred to as hardware VMs) allow the sharing of the underlying physical machine resources between different VMs, each of which executes its own OS. The software that provides the virtualization and controls the VMs is typically referred to as a VM monitor (VMM) or hypervisor. A hypervisor may run on bare hardware (Type 1 or native VMM) or on top of an operating system (Type 2 or hosted VMM).
Cloud computing provides a consumption and delivery model for information technology (IT) services based on the Internet and involves over-the-Internet provisioning of dynamically scalable and usually virtualized resources. Cloud computing is facilitated by ease-of-access to remote computing sites (via the Internet) and frequently takes the form of web-based tools or applications that a cloud consumer or tenant can access and use through a web browser, as if the tools or applications were a local program installed on a computer system of the tenant. Commercial cloud implementations are generally expected to meet quality of service (QoS) requirements of consumers and typically include service level agreements (SLAs). Tenants avoid capital expenditures by renting usage from a cloud vendor (i.e., a third-party provider). In a typical cloud implementation, tenants consume resources as a service and pay only for resources used.
An Internet point-of-presence (POP) is an access point to the Internet that may house servers, routers, gateways, asynchronous transfer mode (ATM) switches, and/or digital/analog call aggregators. An Internet POP may be, for example, part of the facilities of a telecommunications provider that an Internet service provider (ISP) rents or at a location separate from the telecommunications provider. A typical ISP may have thousands of POPs, each of which corresponds to a different physical location. In a POP cloud, it is usually unclear to a tenant where data of the tenant resides, as a location of an access point (e.g., gateway) appears to the tenant to be the location of the data.